Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C43/00—Ethers; Compounds having groups, groups or groups
  • C07C43/02—Ethers
  • C07C43/03—Ethers having all ether-oxygen atoms bound to acyclic carbon atoms
  • C07C43/04—Saturated ethers
  • C07C43/12—Saturated ethers containing halogen
  • C07C43/123—Saturated ethers containing halogen both carbon chains are substituted by halogen atoms
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C17/00—Preparation of halogenated hydrocarbons
  • C07C17/013—Preparation of halogenated hydrocarbons by addition of halogens
  • C07C17/04—Preparation of halogenated hydrocarbons by addition of halogens to unsaturated halogenated hydrocarbons
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C41/00—Preparation of ethers; Preparation of compounds having groups, groups or groups
  • C07C41/01—Preparation of ethers
  • C07C41/18—Preparation of ethers by reactions not forming ether-oxygen bonds
  • C07C41/22—Preparation of ethers by reactions not forming ether-oxygen bonds by introduction of halogens; by substitution of halogen atoms by other halogen atoms
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C43/00—Ethers; Compounds having groups, groups or groups
  • C07C43/02—Ethers
  • C07C43/03—Ethers having all ether-oxygen atoms bound to acyclic carbon atoms
  • C07C43/04—Saturated ethers
  • C07C43/12—Saturated ethers containing halogen
  • C07C43/126—Saturated ethers containing halogen having more than one ether bond

Definitions

• the present invention relates to a new process for the fluorination in liquid phase of unsaturated compounds.
• Fluorinating the double bond is a reaction presenting strong difficulties in practical implementation, due to its highly exothermal character, with the evolution of high amounts of heat, of the order of 107 kcal per each double bond.
• the high reaction energy can lead to strong increases of the reaction mass temperature, within very short times, and hence difficult to control. Locally the temperature can be so high as to cause the breakage of C--C bonds in the product, with the degradation of the same, and the formation of undesired byproducts.
• Another occurring drawback is the dimerization of the product.
• the fluorination is carried out in liquid phase, at a temperature comprised within the range of from -25° C. to +120 ° C., preferably of from -10° C. to +70° C. in presence of a solvent allowing fluorine concentration to be controlled, and acting as a temperature stabilizer, in such way creating such conditions that fluorine may easily react with no delays; consequently, operating is possible with higher fluorine concentrations, thus increasing the reaction rate.
• control of fluorine concentration carried out by adequately diluting gaseous fluorine with inert gases: mixtures containing from 10% to 80% by volume of fluorine are used;
• the radiations have wavelength comprised within the range of from 2200 ⁇ to 8000 ⁇ this causes an increase to occur of atomic fluorine concentration, with the consequence that the dimerization of the olefin is prevented, as well as other side reactions;
• reaction solvent allowing the temperature to be controlled, transparent to the activating radiations used, of low volatility under the reaction conditions, and constituted by a perfluoroether or perfluoropolyether having a molecular weight not lower than 450 and preferably lower than 2000.
• Perfluoropolyethers of class (IV) and (V) are described respectively in U.S. Pat. No. 4,523,039 and in published EP appln. 148,482.
• the perfluoropolyethers belonging to the above said classes must have an average molecular weight comprised within the range of from 450 to 5000 and preferably of from 500 to 2000.
• the process according to the invention is suitable to the fluorinating of perfluorinated linear, cyclic or branched olefins containing from 4 to 12 carbon atoms, with the condition that the branching is not on adjacent atoms, or of perfluoro-vinyl ethers having the general formula ##STR3## wherein R f is a perfluorinated radical of from 1 to 3
• linear olefins which can be used are: linear olefins such as n--C 5 F 10 , n--C 7 F 14 ; branched olefins such as ##STR4## cyclic olefins such as: ##STR5##
• perfluorovinylethers which can be used CF 3 CF 2 CF 2--O--CF ⁇ CF 2 , ##STR6##
• the fluorination tests are carried out within a cylindrical photochemical reactor of 250 cc of capacity, provided with a quartz coaxial sheath for housing a 150-W mercury-vapour lamp type Hanau TQ 150, moreover provided with a bubbling gas inlet, magnetic stirrer, CCl 3 /CO 2 trap, and with a temperature control system both for the reactor and for the sheath system, using perfluorinated liquids (type FC-75).
• the system is kept at the constant temperature of -20 ° C., and the fluorination is carried out with a fluorine stream of 2.5 l/h, diluted with a 7.5 l/h nitrogen stream.
• the flow rate of fluorine is progressively increased up to 5 l/h, and the nitrogen flow rate is reduced to 3 l/h.
• the fluorine present is removed by means of a nitrogen stream; the reaction product is submitted to rectification, and as low-boiling products, 2.5 g of unreacted olefin and 16.7 g of 99% perfluoroisohexane (perfluoro-2-methyl-pentane) having boiling point 57° C. and formula: ##STR7## are obtained.
• the residue is the perfluoropolyether used as solvent.
• I perfluoropolyether of type
• the flow rate of fluorine is progressively increased up to 5 l/h, and the nitrogen flow rate is reduced to 5 l/h; during the same time, the temperature is increased from -20° C. to 0° C.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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Cited By (6)

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• 1985
  • 1985-04-04 IT IT20236/85A patent/IT1200604B/it active
• 1986
  • 1986-03-27 EP EP86104242A patent/EP0196630A1/en not_active Withdrawn
  • 1986-04-03 CA CA000505775A patent/CA1281306C/en not_active Expired - Lifetime
  • 1986-04-03 US US06/847,448 patent/US4684452A/en not_active Expired - Lifetime
  • 1986-04-04 JP JP61076846A patent/JPS61275233A/ja active Pending

Patent Citations (1)

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